| Abbreviation | Definition |
|---|---|
| UDR | Update and Delete Record |
| UEC | Ufop Executive Command |
| UEH | Unified Exception Handler |
| UEN | Update Entity Name |
| UHPA | University of Hawaii Professional Assembly |
| UI | Unsigned Index |
| UI | Unsigned Integer |
| UL | Unsigned Long |
| ULC | Unit- Level Code |
| UM | User Mode |
| UMR | Unlock Machine Room |
| UNEA | United Nations Environment Assembly |
| UNGA | U N General Assembly |
| UNGA | UN General Assembly |
| UNGA | United Nations General Assembly |
| UNIVAC1 | Universal Automatic Computer1 |
| UNPA | United Nations Parliamentary Assembly |
| UPA | UnPack Area |
| UPA | Use all Power Available |
| UPC | Unity Procedure Call |